Which are the fundamental soil-forming process?

[a] Eluviation

[b] Illuviation

[c] Laterization

[d] Humification

Choose the correct answer from the options given below:

Correct option is D

Correct option: (d) — [a], [b] and [d] only
Why these are fundamental:
· Eluviation – Removal (washing out) of fine materials like clay, Fe/Al oxides, and organic matter from upper horizons.
· Illuviation – Accumulation (washing in) of those materials in lower horizons; paired with eluviation.
· Humification – Transformation of plant and animal residues into stable humus; central to A-horizon development.
Why (c) is excluded:
· Laterization is a specialized pedogenic process dominant in humid tropical climates; it is not universally fundamental.
❌ Why other options are incorrect
· Options (1), (2), (3) include laterization or omit humification, which is fundamental across climates.
Key Points
· Fundamental processes operate broadly across soils.
· Eluviation–illuviation work as a coupled system.
· Humification underpins organic matter dynamics.